Well I have been a gymnast all my life, what requires a lot of flexibility, you have to be carefull cuz you can get injured trying to get more and more but be carefull cuz if you do get injured you are going to have less flexibility so .. my tipss are:
1. first do a cardio ( running, bike, jumping a rope ) for like 20 min.. ( to get your muscles warm up)
2. do normal streches without forcing ( like touching your toes with your hands
3. force your self for 5 min in each position
and all has to be slowly dont tray to push into it..hope it helps